Back door / Backdoor
3. An undocumented or hidden entry into a computer system that permits unauthorized access to programs and/or data. Some early voting systems had backdoors that permitted developers to access system functionality without logins.
Source: Glossary - Introduction to Information Technology for Election Officials, U.S. Election Assistance Commission, https://www.eac.gov/assets/1/28/Glossary_IT-Terms_Managing_Election_Technology.pdf
2. An unnoticed, hidden entry into a network or system that allows hackers to “sneak” in without an authorized login or password.
Source: Guide to Cybersecurity as Risk Management: The Role of Elected Officials, Governing Institute, CGI, https://www.cgi.com/sites/default/files/2019-03/guide_to_cybersecurity_as_risk_management_the_role_of_elected_officials_0.pdf
3. Typically unauthorized hidden software or hardware mechanism used to circumvent security controls. (CNSSI-4009) (NISTIR)
Source: The Cyber Glossary, National Security Archive, George Washington University, https://nsarchive.gwu.edu/news/cyber-vault/2018-09-19/cyber-glossary
4. An intentionally designed vulnerability that enables access to a computer system.
Source: U.S. Cyberspace Solarium Commission, March 2020, https://subscriber.politicopro.com/f/?id=00000170-c638-d8f7-a7f1-f63b33510000